Pressure responsive device



OCt. 17, 1933. H, C, KELLOGG 1,930,521

PRESSURE RESPONSIVE DEVICE Filed Jan. 25, 1931 INVENTOR F1' 4. Hel-,bint J Elrm /m GU/ ATTORNEY5 Patented Oct. 17, 1933 UNITED STATES `PATENT or-'FIcE PRESSURE RESPONSIVE DEVICE Herbert C. Kellogg,

Glen P Cowan Detroit, Mich., assi'gnor to Cowan. Detroit. Mich.; Grace A. executrix o! Glen P. Cowan, deceased This invention is a continuation in part of my co-pending application Serial No. 328,268, led December 24, 1928, and relates to pressure responsive devices, and in particular to devices embodying an expansible chamber that is adapted to respond to fluid pressures for the actuation of mechanism operatively associated therewith.

It is often necessary or desirable in the class of devices to which the invention relates, to have means for readily varying the operating characteristics of the device, and it is one of the objects of this invention to provide a pressure responsive device that may be readily adjusted to operate over various pressure ranges and under predetermined operating conditions.

Another object is to provide an improved form of pressure responsive device in which the gradual movement of an expansible contractible element is transformed into a snap action movement.

Another object of this invention is to provide a device of the class described that can be easily and inexpensively manufactured and assembled, and that has a minimum number of parts which are relatively rugged and do not require complicated machining operations for their manufacture.

A further object of this invention is to provide a device of the type described in which a single expansible contractible element serves as an operating means and as an adjustment means for the mechanism with which it is to be associated.

With the above and other objects in view which will be apparent from the following description, the present invention consists in certain features of construction and combinations of parts which will be readily apparent to those skilled in the art to which the invention appertains.

Referring to the drawing in which a suitable embodiment of the invention is illustrated,

Figure l represents a typical set-up of a pair of refrigeration evaporators controlled by my improved pressure responsive device;

Fig. 2 is a fragmentary enlarged section through the valve mechanism showing the valve in open position;

Fig. 3 is a section similar to Fig. 2 with the exception that the valve is shown in its closed position; and

Fig. 4 is a section similar to Figs. 2 and 3 only showing the position of the valve parts substantially at the initial opening of the valve.

As an exempliiication and an illustration of one of the practical uses which can be made of my invention, I have shown it embodied in a control valve for mechanical refrigerators oi the ooded system type using a multiplicity of evaporators connected to a single pump and adapted to maintain diiIerent predetermined temperatures under the control of my improved valve.

In any refrigerating machine operating on the compression system, there are four distinct steps in the cycle of the refrigerant; compression, condensation, reduction of pressure, and evaporation. In refrigerators operating on the flooded system, the four steps in the cycle of the refrigerant are first, heat-laden gas, which is at low pressure and temperature level, is pumped from the top of the float valve housing of the freezing coil unit by the compressor and compressed to a high pressure and hence high temperature level. Second, the high pressure, high temperature gas which the compressor delivers to the condenser gives up its heat to the surrounding air and condenses to a liquid which is still under high pressure. Third, the high pressure liquid is carried to the 'float valve which admits the liquid to the freezing or evaporating coils, filling them completely. This reduces the pressure of the liquid to a low pressure and hence low temperature level. Fourth, the low pressure, low temperature liquid as it receives heat in the freezing coils, evaporates to a low pressure gas. As the gas forms in the freezing coils it rises through the liquid and collects in the top of the valve housing.

Referring to the accompanying drawing in which like numerals refer to like parts throughout the several views, and to Fig. 1 of such a refrigerating system in particular, the numeral 1 indicates the suction line to the conventional compressor (not shown). The compressor is in -turn connected to a'series of cooling coils (not shown) into which the gas is pumped and condensed by the increase in pressure and the loss of heat in the condenser. From the condenser coils, liquid refrigerant is usually led to a liquid reservoir (not shown) which in turn communicates with the high pressure liquid line 2 of Fig. l.

The high pressure liquid in the line 2 is led to two float valves indicated by the numerals 3 located at the inlet side of the evaporator coils 4 and 5. A control valve 6 is located in the suction line 1 at a point close to the evaporator 4. Thevpurpose of the valve 6 is to maintain predetermined temperature in the coils to which they are connected. 'I'he manner in which this is accomplished will be presently .described in v detail.

The compressor, cooling or condensing coils, liquid reservoir and automatic mechanism governing the operation of the compressor may be of any suitable type. These elements are not illustrated because they do not form a part of this invention, and at present are not necessary for its understanding.

Referring to Figs. 2, 3 and 4, which illustrate the structural details o1 the control valve 6, the numeral 9 indicates a valve body, the upper portion of which threadably receives a cylindrical housing 10 that threadably carries a cap 11. The housing 10 and cap 11 provide a housing for an expansible contractible element or bellows 12, the upper end of which is sealed by a disc 13. IIhe lower end of the bellows 12 is sealed by the top of the valve body 9. 'I'he disc 13 is movable within the housing l0, its upward position being limited by a boss 14 formed on the cap 1l and being resisted by a coil compression spring 15 surrounding the boss 14 and extends between the cap 11 and ldisc 13. A conical shaped cam 16 is threadably secured in the central portion of the disc 13 and cooperates with a pair of rollers 17 that are rotatably mounted on suitable resilient supporting pins 18 carried in the end of a cylindrical valve head guide 19, which is integrally formed with the valve head 20. The disc 13 is also provided with a central guide pin 21 which is slidably received within an opening formed in the boss 14.

Excessive downward movement of the disc 13 is limited by a cylindrical stop 26 surrounding the rollers 17and mounted on the top of the body 9. Interposed between the cylindrical stop 26 and the bellows 12 is a coil compression spring 27 which engages the valve body 9 and under side of the disc 13 to provide a cushion action, the spring 27 being of lesser resistance than the spring 15.

The valve body 9 is provided with an inlet opening 23 and an outlet opening 24 which lead into a valve chamber 22 extending through the body 9. The valve head and valve seat are tapered and of such size to provide an opening equivalent to the size of the conduit l. A passage 25 is formed in the valve head 2l and its guide 19 to permit the fluid under pressure at the inlet side of the valve to ow into the interior of the bellows 12 and act against the disc 13 and thereby expand the bellows 12. 'Ihe lower end of the valve body 9 is closed by a suitable cleanout plug 28, and this plug at the point where the valve head 20 seats against it in open position as shown in Fig. 2, is recessed at 29 to permit the ilow of fluid to the under side of the valve head 20 `and thence through the passageway 25.

It will be observed that variations in the uid pressure acting against the disc 1'13 will cause the bellows 15 to expand or contract in accordance with the opposing pressure of the spring 15. The pressure of the spring 15 may be manually adjusted by raising or lowering the housing l0 by Maasai the valves is to control the temperature of the evaporator or evaporators where more than one valve is used, by means of the pressure in the evaporator to which the valve is connected, such as where it is desired to prevent the temperature from going below a predetermined point.-

The valve is so designed as to take advantage of the increased suction pressure on any of the evaporators operating under high temperatures. This is accomplished by a quick opening and a quick closing action of the valve, so that when gas is being removed from an evaporator the valve controlling the temperature or pressure will be wideopen. This action results in increased pressure to the compressor with an increase in the capacity.

Valves heretofore were designed as pressure reducing valves and consequently did not increase the suction line pressure to the compressor when gas was being taken from the evaporator.

The snap action on the valve is also desirable asV such an action assists in keeping the valve clear of foreign material which might become lodged between the valve and seat, causing it to leak. 'Ihe valve in this design is balanced to prevent a change in maintained pressures with widely varying control settings.

The valve proper is so designed that it may be readily removed through the opening closed by the plug 28 or reseated. With its removal, all working parts which it may be desirable to replace are easily removable. The valve is exceedingly simple in construction, compact in size and easily adjusted.

As a matter of explanation, we will assume that the valve is used in connection with a soda fountain where an evaporator such as'5 is adapted to be maintained at ice cream temperatures at approximately zero degrees, and that the evaporator 4 is to be maintained at approximately 20 degrees. We will further assume that the compressor is running, and that the temperature of the evaporator 4 is above 20 degrees. Under these conditions the valve head 20 is in open position, as shown in Fig. 2. As the pressure in the evaporator 4 is being reduced, the bellows l2 is collapsing because of this reduction of pressure, and when the pressure is reduced to a point which corresponds to 20 degrees the bellows collapses to substantially its minimum, at which time the cam 16 spreads the rollers 17 apart by reason of the resiliency of the spring supports, and as the widest portion of the cam passes the center line of the rollers the resiliency of the spring pins 18 causes the rollers 17 to move along the upper surface of the cam, thereby quickly moving the valve head to its closed position against the seat as shown in Fig. 3. 'Ihis closes the suction line to the evaporator 4 and permits the compressor to continue its cooperation with the evaporator 5. As the evaporator 4 warms up, pressure in the suction line increases and this pressure is transmitted through the recesses 29 in the plug 28 to the passage 25 in the valve head 20 and guide 19 and thence through the small opening therein into the interior of the bellows 12. This pressure when greater than the difference between the predetermined pressure of the springs l5 and 27, acts against the bellows head disc 13, thus causing the bellows to expand.

During this expansion, thecam 16 moves relative to the rollers 17 since the valve head 20 is seated against further movement in that direction, and at the instant that the high points of the cam pass the center line oi the rollers the rollers, because of the resiliency of the pin supports 18, slide along the lower conical surface oi' the cam and thereby quickly move the valve head 20 to its open position, as shown in Fig. 6. The position of the operating parts at the initial opening of the valve is shown in Fig. 4. In other words, the rollers 17 spring past the dead center position oi the cam 16 when the pressure within the bellows has increased suillciently, thereby quickly pushing the valve 20 to its open position. This operation may be repeated several times while the compressor is still operating in connection with the evaporator 5.

Now we will assume a condition in which the evaporator 5 is at the desired temperature and the temperature of the evaporator 4 is above the set temperature of 20 degrees. In this case the compressor is not in operation since it is controlled by the temperature of the evaporator 5 which is at zero degrees. In this case the valve mechanism opens in the same manner as previously described, because of the increase in pressure in the suction line. 'I'his then opens the connection between the two evaporators, thus equalizing the pressures therein and equalizing the temperatures. II this equalized pressure is greater than the pressure from which the controlling mechanism is set to place the compressor in operation, it will consequently cause the pump to again be set in operation and the valve to be closed when the pressure corresponding to 20 degrees is reached, as previously described. The compressor will then operate until the pressure within the evaporator 5 has again reached the pressure corresponding to the temperature of zero degrees that is to be maintained in the evaporator 5.

This quick opening and quick closing action on the part of the control valve described will materially increase the capacity of the compressor employed, particularly where a high percentage of the total load must be handled by the higher temperature evaporator.

It is obvious that when a dierent temperature is to be maintained in the evaporator 4, the valve can be set to correspond to the desired temperature by merely rotating the housing 10 to increase or decrease the pressure of the spring 15 as the case may be.

Furthermore, it is to be understood that the particular form of apparatus shown and described, and the procedure set forth are presented for purposes o! explanation and illustration, and the various modiilcations of the apparatus and procedure can be made without departing from my invention as defined in the appended claims.

What I claim is:

1. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end being closed, an expansible-contractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding t with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said es. a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movement of said valve head relative to said Beat upon expansion or contraction oi' said bellows by the pressure of the iluid Ain said inlet passage.

2. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end r`being closed, an expansiblecontractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, spring means tor yieldably resisting expansion ot said bellows, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding nt .with the walls o1' said chamber, a reciprocable valve head carried by said guide and being cooperatable with A said seat to permit open communication and 90 completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and "05 the closed end of said bellows for providing rapid l movement of said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the fluid in said inlet passage.

3. In a pressure responsive valve, a valve body 110 having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end being closed, an expansiblecontractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, spring means for yieldably resisting expansion of said l bellows, means for increasing or decreasing the 1 pressure of said spring means, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding t with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said passages, a passage through .said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movement oi said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the fluid in said inlet passage.

4. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said 140.

passages, one end of said chamber being open and the other end being closed, an expansiblecontractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, means for axially guiding the closed end of said bellows during movement thereof, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding flt with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movement of said valve head relative to said seat upon expansion or contraction ot said bellows by the pressure ot the iluid in said inlet passage.

5. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat 'in said chamber interposed between said passages, one end of said chamber being open and the other end being closed, an expansible-contractble bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, spring means for yieldably resisting expansion movement oi.' said bellows, means for decreasing or increasing the pressure of said spring means, means for axially guiding the closed end of said bellows during movement thereof, a reciprocable guide in said chamber between said passages and the open end of said chamber' and having a sliding fit with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movementrof said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the fluid in said inlet passage.

6. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end being closed, an expansible-contractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, a housing carried by said body to surround said bellows, spring means interposed between said closed end of said bellows and the end oi said housing for yieldably resisting expansion movement of said bellows, a reciprocable guide in said chamber between said passages and the open end of said chamber and having .a sliding ilt with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat tol permit open communication and completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve -head and the closed end o! said bellows for providing rapid movement of said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the fluid in said inlet passage.

7. In a pressure responsive valve, a valve bodyhaving a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end being closed, an eXpansible-contractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, a housing carried by said body to surround said bellows, spring means interposed between said closed end of said bellows and the end of said housing for yieldably resisting expansion movement of said bellows, at least a portion of said housing being rotatable to increase or decrease the pressure of said spring means, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding t with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movement of said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the iiuid in said inlet passage.

8. In a pressure responsive valve, a valve body having a valve chamber therein, inlet and outlet passages opening into said chamber, a valve seat in said chamber interposed between said passages, one end of said chamber being open and the other end being-closed, an expansible-contractible bellows member closed at one end and secured at its opposite end to said body to enclose said open end of said chamber, a closed housing carried by said body to surround said body, telescoped relatively movable cooperating parts carried by said housing and the closed end of said bellows for axially guiding the closed end of said bellows during movement thereof, a reciprocable guide in said chamber between said passages and the open end of said chamber and having a sliding iit with the walls of said chamber, a reciprocable valve head carried by said guide and being cooperatable with said seat to permit open communication and completely prevent communication between said passages, a passage through said valve head providing communication between the interior of said bellows `and said inlet passage, and snap action mechanism between said valve head and the closed end of said bellows for providing rapid movement of said valve head relative to said seat upon expansion or contraction of said bellows by the pressure of the iluid in said inlet passage.

HERBERT C. KELLOGG. 

